Refrigerating apparatus



April 28, 1925..

G. BAYER ET AL REFRIGERATING APPARATUS Filed Dec. 19, 1923.

Patented Apr. 28, 1925.

. UNITED STATES GAUDENZ BAYER AND CARL HOCHHERZ, or AUGSBURG, GERMANY, AssrGNoRs TO THE FIRM GEBRtTDEB. BAYER,

1,535,758 PATENT OFFICE.

OF AUGSIBUBG, GERMANY.

REFRIG-EEATING APPARATUS.

Application filed December 19, 1923. Serial No. 681,526.

To all whom it may concern:

Be it known that we, GAUDENZ BAYER and CARL HOCHHERZ, both citizens of the German Republic, and residents of Augsburg.

Bavaria, Germany, have invented certain new and useful Improvements in Refrigen ating Apparatus, of which the following is a s ecification.

3m invention relates to refrigerating apparatus, more particularly of the absorption type of refrigerating apparatus, and has for its main object the abolishment of check valves, expansion valves and, in general, of all moving parts which are liable to get out of order, which complicate the arrangement and require skilled, attendance.

In an apparatus according to our invention these draw-backs are entirely absent, and in a preferred form of the invention we connect the still-absorber and the evaporator through. the condenser, so that the ammonia gas or the like refrigerating agent, after having been developed in the still-absorber, may flow into the condenser in order to be liquefied and to thence flow into the evaporator, from .which it passes back into the still-absorber after evaporation It is one of the objects of the invention to improve the connection between condenser and evaporator in so far as to enable the formation of a liquid seal by means of the liquefied refrigeratmg agent, which seal would act as a valve and prevent the gas taking its way from the evaporator into the condenser during the absorption period.

The said liquid seal also renders it possible, without the necessity of check valves, to convey the liquid contents of the evaporator, andthus any water which maybe contained therein, into the still-absorber, and it is a further object of our invention to provide simple and efiicient' means whereby such conveyance of the liquid maybe carried out whenever desired.

In the accompanying drawing:

Fig. 1 is a diagrammatic sectional view of an apparatus constructed in accordance with our invention,

Fig. 2 is a detail, also diagrammatic, of a modified form of'our invention and shows a different arrangement for the formation of the liquid seal,

Figs. 3 and 4 are two further m'odifica-.

tions of the apparatus, likewise in diagrammatie sectional view, 11]. which means are provided to enable the return of the liquid from the evaporator into the still-absorber at will.

Referring to Fig. 1, a is the still-absorber resembling a kind of boiler and which mav be heated for example by means of the electric heating elements I). The usual cooling device for the still-absorber which comes into operation during the absorption process 1s denoted by 0. A tube d leads from the top of the boiler to the condenser e which latter is connected to the lower portion of the evaporator f by a tube f], so that a liquid seal will be formed in this connec tion member. In the example of Fig. 1 this is rendered possible by the provision of a loop h in the tube 9, terminating closely above the bi ttom of the evaporator 7 so as to have its opening permanently submerged in the liquid. From' the top of the evaporator a conduit 13 leads upwardly into the still-absorber a and terminates into a distributor is below the liquid level in the said vessel.

Fig. 2 shows the vital parts of a modified arrangement for the formation of a liquid seal between condenser and evaporator. In this modification thedischarge pipe (7 of the condenser terminates into a liquid trap Z which preferably is arranged within the cooling range of the evaporator f, or of the refrigerating plant respectively, so as to open into the evaporator, The trap remains permanently filled with the liquified refrigerating medium, which does not evaporate there.

The arrangement according to the invention operates in the following manner: The gases which emanate from the still-absorber during the boiling process pass into the condenser e where they are caused to condense and collect primarily within the liquid recipient h, or Z respectively, arranged between condenser and evaporator,"after which they enter the evaporator. For the whole dura- 'tion of evaporation and absorption there 5 the evaporator through tube 71 into the absorber.

However, even if a water separator were provided in such an arrangement, experience as shown that water would yet enter the evaporator in course of timeand thus affect its efiiciency. It is therefore necessary to remove all liquid contents of the evaporator, including any water which may have collected therein, and to return same to the still-absorber. In a plant according to the invention this may be accomplished, owing to the provision of the liquid seal, simply &y the arrangement of special conduits.

W0 examples of such an arrangement are diagrammatically shown in Figs. 3 and 4 of the drawings. In both these figures the general arrangement of the apparatus corresponds to that shown in Figs. 1 and 2, in which a liquid seal is formed in the connection between the condenser e and the evaporator f.

In the arrangement shown in Fig. 3 the to of the evaporator f is connected to the stlll-absorber a b means of a tube i as in the example shown in Fig. 1. Apart from the said tube another conduit m is provided which reaches down to the bottom of the evaporator and serves to return water from the evaporator to the still absorber. It will be seen that the clear diameter of tube 2' is so narrow, as compared with that of the tube m, that the diflerence of pressure between the evaporator f and the absorber a during the absorption period will normally just be sufficient to allow of the vapours passing through the said tube 2', while it will not be sufficient to force the liquid through the tube m, since the column of liquid contained therein would be too heavy to be lifted by the normal working pressure. However, by artificially increasing the difierence of pressure between the evaporator and the absorber, gas will suddenly develop in such large quantities that the increase in pressure can no longer be compensated through the narrower tube 6, with the result, that the the evaporator.

liquid contents of the evaporator f Wlll he precipitated from the evaporator along the path of least resistance. namely through the pi e m into the still-absorber a. Such artificial increase of pressure may be obtained either by the application of a particularly efi'ective cooling to the coil 0 within the still absorber a, or by the application of heat to Since the tube m is arranged to dip right down to the bottom of the evaporator f any water collected therein will be forced up the said tube, which evidently is the purpose of the arrangement, whilst at the same time the provision of the liquid seal in the connection pipe 9 prevents the liquid from taking its way through the condenser e. For the purpose of the proper working of the apparatus it is advisable to make the cross section of the tube 9 so narrow, or to provide corresponding obstructions or restrictions in its clear diameter, as to afford a considerable resistance to the passage of the liquid into the condenser which, however, would not hinder the slow trickling down process of the liquefied refrigerating medium from the condenser into the evaporator.

In order to artificially increase the difference in the pressure between evaporator and absorber, means may be provided in the former to enable hot water being filled in, such means, for example, as the cup 72 shown in Figs. 3 and 4. Such cups are sometimes used in the smaller type of refrigerating apparatus for the purpose of making ice and they may now be used for occasionally effecting an increase in the gas pressure. If, as mentioned before, the cross sections of the conduits i and m are compensated by a certain restriction at the entrance of tube '5 within the evaporator 7 then the tube m may be joined to the tube 71 at any place of the latter above the said entrance. In Fig. 3 this is indicated by the broken lines at the top of the figure.

In the modification of Fig. 4 a single connection i only is shown between the evaporator and the absorber, similar to that shown in Fig. 1, but with the difference, that this tube 1' has an extension 0 which dips down as far as to the bottom of the evaporator. Above the normal liquid level and within the evaporator f a small opening 79 is provided in the tube z'0 which, under normal working pressure, is sufficient to permit the passage of the gas into the absorber. However, the clear diameter of the opening p in the tube io is not large enough to-=a05 pass such large volumes of gas as would be spontaneously developed by an artificial increase of pressure and, therefore, the gas in this case would press upon the liquid contents in the evaporator and precipitate same through the extension 0 and the tube 1'. into the absorber. It will be evident. that owing to the liquid seal in the conduits g, h and the resistance offered by the narrow cross sections of these conduits, such artificial pressure increase will not be able to take its way through the condenser e to any ap preciable extent.

It. will also be evident that during the evaporation period the liquid standing in the still-absorber with the evaporator, means in the connection between condenser and i evaporator adapted to collect the liquefied refrigerating medium and to thus form a liquid seal, a directly communicating tube conduit between still-absorberand evaporator emanating from the still-absorber below the liquid level of same and passing through the evaporator so as to terminate v at'the bottom of same, and an orifice in the wall of the said tube within the evaporator and above its liquid level, and having -a diameter smaller than that of the tube conduit.

'2. A refrigerating apparatus of the absorption type, including a still-absorber, an evaporator, a connecting means for the flow of refrigerant from the still-obsorber to the evaporator, and including a condenser,

and separate connecting means for the return of refrigerant from the evaporator to the still-absorber, and having a. comparatively small port at the-upper part of the evaporator for the normal flow of vaporized refrigerant durin the cooling period and a larger port at t e lower part of the evaporator for the flow of liquid upon abnormal heating, high rate 0 andhigh pressure in'the evaporator.

' eluding a stil the upper part of the evaporator and a.

permanently open liquid port at the lower part of the evaporator, and separate conmeans for the flow of refri erant nectin is upperpart of the still-absor r to the evaporator, said last mentioned means including a condenser and a liquid seal;

4. A refrigerating apparatus of the 1ntermittently acting absorption type, comprising-asingle valveless and permanently open fluid circulating circuit including a still-absorber, an evaporator including ach-amber adapted to receive the main body of liquefied refrigerantjrom the condenser during theheating period, and exposing a comparatively large area of said refrigerant for evaporation during the cooling period, connecting means for the flow of gas from the upper part of the. evaporator to thelower .part of the still-absorber, and

connecting means for the flow of gas from the upper part of the still-absorber tothe eva orator, said last mentioned means in 'clu ing a condenser, and means beyond the condenser in the direction of the flow of the as for maintainin a small body of liqui with a very smal surface area exposed in said connecting means, whereby evaporation, 7

only the gas resulting from eva ration at said surface will return throug said condenser to the still-absorber.

5. A refrigerating apparatus of the intermittently acting absorption type, comprising a single valveless and permanently open fluid circulating circuit including a still-absorber, an evaporator including a chamber adapted to receive the main bod of refrigerant during the heating perio connecting means for the flow of gas from the upper part of the evaporator to the lower part of the still-absorber and connecting means for the flow of gas from the upper part of the still-absorber to the evaporator, said last mentioned means including a condenser, and being adapted beyond said condenser to retain a small quantity ofthe liquefied refrigerating medium and to thus form a liquid seal preventing return flow of evaporated refrigerant from the" evaporator through the condenser to the still-absorber.

6 LA refrigerating apparatus of the intermittently acting absorption type, including a still absorber, an evaporator, a condenser arranged in circuit between the stillabsorber and the evaporator, and valveless permanently open communication means between the-evaporator and the still-absorber, and having a small outlet from the upper part of the evaporator and an outlet from the lower part of the evaporator, the relative areas of said outlets being such that the first mentioned outlet permitsthe free esca of gas during normalcooling operation, but permits the development of pressure in the evaporator and the forcing of liquid through said second mentioned outlet upon abnormal high rate of evaporation in the eva orator.

7. A re rigerating apparatus of the intermittently acting absorption type, includ ing a still-absorber, an evaporator, valveless, ermanentlyopen communication means etween the evaporator and the stillabsorber, and having an outlet from the upper .part of the evaporator and an outlet from the'lower part of the evaporator, the relative areas of said outlets being such that the first mentioned outlet permits the free escape of gas during normal cooling operation, but permits the development of pressure in the evaporator and the forcing of.

liquid through said second mentioned outlet upon abnormal high rate of evaporation in the evaporation, and a second communication means between the still absorber and the evaporator, and including a condenser and 

